Lighting Keyboard and Backlight Module

1. A backlight module configured to illuminate at least one key cap, the backlight module comprising: a light emitting unit; a light guide plate having a light guide hole for accommodating the light emitting unit; and a lighting board having at least one pair of pads connected to the light emitting unit respectively, the lighting board comprising a first reflective layer surrounding the light emitting unit and at least partially covering the at least one pair of pads; wherein each of the at least one pair of pads has a plurality of branches and at least one hollow area, the at least one hollow area overlaps with at least one part of the light emitting unit, and at least one lighting area is located between the at least one pair of pads.

2. The backlight module of claim 1, wherein the at least one lighting area is a portion of the lighting board exposed between the at least one pair of pads.

3. The backlight module of claim 1, wherein the light emitting unit comprises a plurality of dies, and the lighting board has a plurality of pairs of pads respectively connected to the plurality of dies.

4. The backlight module of claim 3, wherein the lighting board has a plurality of sub-traces, and each pair of the plurality of pairs of pads is electrically connected to two of the plurality of sub-traces respectively.

5. The backlight module of claim 4, wherein the at least one lighting area is located between two sub-traces connected to an identical pair of pads.

6. The backlight module of claim 4, wherein the at least one lighting area is located between two sub-traces connected to different pairs of pads.

7. The backlight module of claim 4, wherein the lighting board further has two main traces electrically connected to the plurality of sub-traces respectively, the lighting board further comprises a pair of outer micro-structure regions apart from each other and located on the first reflective layer, and the pair of outer micro-structure regions are located beyond the two main traces.

8. The backlight module of claim 4, wherein the first reflective layer covers the plurality of sub-traces.

9. The backlight module of claim 4, wherein the lighting board further comprises a pair of micro-structure regions apart from each other and located on the first reflective layer, and the pair of micro-structure regions does not overlap with the plurality of sub-traces.

10. The backlight module of claim 3, wherein the plurality of dies are arranged consecutively with short side to short side or long side to long side.

11. The backlight module of claim 3, wherein the plurality of dies are arranged in a relatively tilted manner.

12. The backlight module of claim 1, wherein an inner ring section of the first reflective layer at least partially covers the plurality of branches and the at least one hollow area, and the inner ring section reflects and diffuses light of the light emitting unit.

13. The backlight module of claim 1, wherein the lighting board further comprises a pair of micro-structure regions apart from each other and located on the first reflective layer, the pair of micro-structure regions jointly surround the at least one pair of pads, and the pair of micro-structure regions reflect and diffuse light of the light emitting unit transmitted through the light guide plate.

14. The backlight module of claim 1, wherein at least one of the plurality of branches is not fully covered by the first reflective layer, and an exposed section of the plurality of branches of each pad reflects and diffuses light of the light emitting unit.

15. The backlight module of claim 1, wherein at least one part of the first reflective layer is located in the light guide hole.

16. The backlight module of claim 1, wherein the backlight module comprises a shielding sheet, and the shielding sheet comprises an inner reflective section overlapping with the first reflective layer.

17. The backlight module of claim 1, wherein at least one of the plurality of branches of the at least one pair of pads surrounds at least one part of the light guide hole.

18. The backlight module of claim 1, wherein the first reflective layer has a reflective layer hole, and the at least one hollow area of the at least one pair of pads surrounds and/or overlaps with the reflective layer hole.

19. The backlight module of claim 1, wherein the first reflective layer has a reflective layer hole, and the reflective layer hole is located between the light emitting unit and the light guide hole.

20. The backlight module of claim 1, wherein the first reflective layer has a reflective layer hole, and a part of the first reflective layer overlapping with the at least one pair of pads is located between the reflective layer hole and the light guide hole.

21. A lighting keyboard comprising: a plurality of keyswitches, each of the plurality of keyswitches having a key cap; and the backlight module of claim 1 located below the plurality of keyswitches.